shackelton



April 120.1921. 1,624,630

W. J. SHACKELTON INDUGTANCE DEVICE AND METHOD FOR MANUFACTURING THE SAME Filed May 21. 1921 2 Sheets-Sheet 1 April 12,1927. 1,624.630

. W. JLSHACKELTON R MANUFACTURING THE SAME INDUCTANCE DEVICE AND METHOD F0 Filed May BL. .1221

2 Sheets-Sheet 2 Patented Apr. 12, 1927.

UNITED STATES PATENT OFFICE.

WILLIAM J. SHACKELTON, Oi! SCOTCH PLAINS, NEW JERSEY, ASBIGNOB TO WESTERN ELECTRIC COMPANY, INCORPORATED, OF NEW YORK, N. Y., A OOBPORATION OI new YORK. I

INDUCTANCE DEVICE AND METHOD Application filed Kay 21,

This invention relates to inductance devices and their manufacturing methods of the type known in the art as retard coils. loading coils, transformers, and the like.

Inductance coils hitherto employed have been usually constructed by winding the wire conductor around a frame of rectangular or toroidal form for example, so that the .windings substantially surround the magnetic core material.

It is an object of this invention to provide a simpler, more compact and more easily manufactured inductance device than can be obtained by the above method and this object is obtained by reversing the usual space relation of the windings and the magnetic material in such a manner that the magnetic material entirely surrounds the windings. The complete imbedding of the wlndings 1n the magnetic material is of especial importance in case the coils areto be employed as loading coils, "for example, in a telephone system, since this novel structure completely screens each coil from all external disturbances from foreign potentials in associated apparatus. In the preferred embodiment of this invention, this is accomplished by winding the wire conductor into a coil of the desired diameter and forming the magnetic material into two blocks, each containlng a circular groove in one face so that the coiled wire will snugly fit into the grooves when the two blocks are placed with their two grooved faces against each other. Such a structure is particularly advantageous for use as a loading coil for a submarine cable, for example, where only a limited amount of space in a diametrical direction 1s available. The magnetic material employed should 7 have as high permeability as possible, consistent with low magnetic losses, and for that reason the iron dust magnetic material described in the Speed, U. S. Patent No. 15,274,952 is preferably employed, not only because of its suitability from a magnetic standpoint, but also on account of the ease with which it may be moulded into any desired shape. Holes in the magnetic material should, of course, be provided for the leading-in conductors of the coil.

This invention will be better understood by reference to the following detailed de- 2013. mnorao'ronme THE sum.

BEISSUED scription taken in connection with the accompanying drawings, in which Fig. 1 illustrates the inductance device of this invent1on employod as a loading coil for a submar ne cable; Fig. 2 is a cross section of a portion of Fig. 1; Fig. 3 is a schematic drawmg of the circuit connections for the submarine cable of Fig. 1; Fig. 4 represents a modified form of this invention particularly adapted for loading telephone lines; Fig. 5 represents this invention employed as an ordlnary retard coil, and Fig. 6 re resents this invention employed as a two-winding step-up transformer.

Thesubmarine cable illustrated in Fig. 1, comprlses a suitable armor or other covering 10, surrounding four signaling conductors 11, 12, 13 and a fourth conductor opposite conductor 12, but not shown in Fig. 1, although shown in Fig. 3. In accordance with this invention these four signaling conductors are loaded according to the Pupin system of loading by means of two inductance devices 16 and 17. Inductance device 16 comprises three cylindrical blocks 18, 19 and 20 which are held together by any suit able clamping means such as members 22 in one end of which are provided tightening screws 23. The two adjacent faces of blocks 18 and 19 contain circular grooves in which a coil of wire 25 is adapted to be placed. A similar inductance coil 26 is located in cor-. responding grooves in the adjacent faces of blocks 19 and 20. The inductance device 17 is similar to inductance device 16 and comprises three cylindrical blocks of magnetic material '28, 29 and 30 in which are imbodded two coils of wire 31 and 32. The two inductance devices 16 and 17 are separated from each other a suitable distance bya block 33 of insulating material, such as wood.

As shown more clearly in Fig. 3, a coil 31 is connected in series with conductor 11 of the submarine cable, coil 32 in series with conductor 14-, coil 26 in series with conductor 12, and coil 25 in series with conductor 13. As shown in Fig. 1 the four conductors of the cable pass through apertures in the blocks 18, 19, 20,23, 28, 29 and 30, centrally located therein, in a direction parallel to the length of the cable. Such an arrangement has obviously a particular advantage in submarine cables since the signaling conductors thereof are deviated from their natural course only in short connections from the center of the loading units to the coils of wire. As shown in Fig. 1, each signaling conductor of the cable is connected in series with one of the coils of the wire by a leading-out conductor and, a leading-in conductor located in small apertures passing from the centrally located opening in the blocks -of magnetic materialup to the grooves in the blocks wherein the coils of wire are found.

If desired, the two inductance devices 16 and 17 may also be employed for loadingfhe phantom circuit as well as the two physical circuits formed from the four conductors 11 to 14 inclusive. This loading of the phantom circuit by these two inductance devices is made possible by the fact that since the two coils of each pair aid for side circuit currents, it is obvious that for phantom circuit currents there will be opposing fluxes due to coils 25 and 26 and also opposing fluxes due to coils 31 and 32. The amount of flux interlinkage due to these effects will depend upon the distance between the two coilsof each loa'iing unit. The greater the distance between the two coils, the greater will be the resultant phantom flux and hence, the greater will be the ratio of phantom to side circuit loading. In Fig. 3, signaling devices 36 and 37 may be employed for signaling over the physical circuit com rlsing conductors 12 and 13, while the signaling devices 38 and 39 may be employed for the transmission of signals over conductors l1 and 14 and devices 40 and 41 may, by well known connections, be employed in signaling over the phantom circuit derived from the four signaling conductors of the cable. It is obvious that each of the pairs of coils of wire 25 and 26, 31 and 32 should be adjusted to have such an inductance value as to load the signaling conductors of the cable to the proper extent according to the Pupin system. Inasmuch as loading systems are now well known in the art, it is not believed necessary in this specification, to recite a specific example of what values these inductances should have for the loading of a submarine cable of a given type.

In order to make each of the inductance devices 16 and 17 as compact as possible for a desired value inductance, the magnetic material employed should be of as high permeability as possible as is consistent with low magnetic losses. For example, they are preferably composed of iron dust core material of the type described in the U. S. Patents Nos. 1,274,952 to Speed, 1,286,965 to Elmen and 1,292,206 to Woodrufl, which material -is not only suitable from a magnetic standpoint, but also is capable of being moulded into any desired shape. Such a material therefore can be readily formed to provide the necessary grooves and apertures required for such an inductance device as that described above.

Fig. 2 is a cross section of inductance device 16, taken along the line marked by the arrows and serves to illustrate more clearly the space relation of the various parts of the inductance device described in detail above.

Fig. 4, illustrates a modified type 01 the inductance device of this invention which may be employed, for example in loading duplex telephone lines. The inductance device 45 of Fig. 4, comprises three blocks of magnetic material 46, 47 and 48 which are grooved in a similar manner as the blocks of Fig. 1 to provide for the imbedding therein of the two inductance coils 49 and 50. After the inductance coils have been imbedded in the three blocks, they may be assembled and held in position with respect,

to each other by a bolt 51, for example, passing through an opening in the three blocks parallel to the axis of the two inductance coils. The two telephone line conductors 53 and 54 of the one physical circuit may be connected to the inductance coils 49 and 50 by lead-in wires passing through small apertures 55 and 56 in the blocks of magnetic material, the leading-out conductors passing through corresponding apertures 57 and 58 on the opposite side of the block. The two conductors 60 and 61 of the second physical circuit may be similarly loaded by an inductance device 63 comprising inductance coils 64 and 65 imbedded in three blocks 66, 67 and 68 of appropriate magnetic material.

Inasmuch as the question of space in a diametricaldirection is not so vital in loading a .telephone line, as in loading :1 sub marine cable, inductance devices 45 and 63 are shown to have a much greater dimension in a direction at right angles to the axis of the coils than they have in a direction parallel to this axis. This form is advantageous for the reason that it facilitates assembly of a large number of coils in one case. In comparing the inductance devices of Fig. 4 with those of F ig. 1, it should be noted that in Fig. 1, the dimensions of each of the devices a core as shown, for example, in the Speed patent above mentioned. From the above description it will be read- 11y understood that it is frequently advanductors 86 and 87 being tageous to employ the inductance device of this invention not only as a loading coil but also for other purposes such as retard coils, transformers, and the ike.

Fig. 5, for example, illustrates'an inductance device employed as a retard coil for an electric circuit comprising conductors 7 5 and.

shown to consist of. a greater number of turns of wire than its associated coil 82. This device therefore ma be readily employed as a step-up trans ormer in an electric circuit, conductors 84 and 85 bein connected to the primary winding 82 an conconnected to the secondary winding. 83. nasmuch as the two coils 82 and 83 are positioned side by side in the grooves of the magnetic material it follows that there is a maximum of interlinkage of the fluxes of the primary and the secondary windings. This type of transformer also possesses an advantage over the type of transformer in-which the core material is surrounded by the coiled wire for the reason that the transformer of Fig. 6 has practi cally no-stray lines of force which might become troublesome in causing cross talk between adjacent apparatus located in different circuits.

What is claimed is:

1. A block of irondust core material, and 1 a .coil of wire imbedded in said block.

divided magnetic material, and a coil of wire substlantially entirely imbedded in said materia 3. In a signaling stem, a submarine cable, an inductance d ice for loading said cable comprisin a plurality of inductance coils havin their use parallel to the length of said cab e, and of iron dust material substantially entirely imbedding. said 00] s.

netic core comprising 2. An inductance device comprising finely- 4. A signalin stem com risin a plurality of signaling cfiiiductors, loadin device for said conductors comprising a p urality of coils of wire, said device having an opening therethrough located parallel to the axes of said coils and surrounded by said signaling conductors passing through said opening.

5. A- si aling system comprising a submarine ca le, a loading device for said cable comprising a plurality of inductance coils surrounded by magnetic material, said magnetic material having an opening therethrough parallel to the axes of said coils and surrounded by said coils, the conductors of said cable passing through said opening.

6. A signaling system comprising aplurality of signs ing conductors, means for loading two physical circuits and a derived phantom circuit formed from a plurality of said conductors, said means comprising a plurality of inductance coils imbedded in ma etic material of a uniform composition, sai coils being located in said magnetic material in such a position with respect to each other that an interlinka e of the fluxes of a plurality of said coils tz dies place.

7. An inductance device comprising a c lindrical coil of wire and a core completely surrounding said coil, at least that portion of the core within the coil being composed of; comminuted magnetic materal.

8. An inductance device for signaling circuits comprising a' coil of wire, a core of magnetic material in which the eddy current I losses are ne ligible completely surrounding the coil, at east that portion of the core within the coil being composed of iron dust 'core material.

9.- A leading coil for signaling circuits comprising a coil of wire, and a closed magfinely divided magnetic material comp etely embedding said coil and insulated therefrom. p

10. An inductance device comprising a coiled conductor and an envelope of comminuted magnetic material substantiall enclosing aid coiled conductor and insu ated therefrom.

In witness whereof, Ihereunto subscribe my name this 19th day of May A. D., 1921.

WILLIAM J. SHACKELTON.

said coils, 

